The present invention relates to a method of producing a vibration or noise attenuating metallic material suitable for use in acoustic instruments and various industrial equipments which require a suppression of vibration and noise.
Hitherto, it has been proposed to form a multiplicity of minute cracks in the surface of a metallic material by effecting an intergranular corrosion, and to use this metallic material as a vibration attenuating material. However, in some cases, it is not possible to obtain the desired state of minute cracks by the intergranular corrosion. This conventional method, therefore, is applicable only to limited materials.
As a countermeasure, there has been proposed a method of producing a vibration attenuating metallic material which does not rely upon the intergranular corrosion. More specifically, this method makes use of a drawing or rolling work. A multiplicity of grooves are mechanically formed in the surface of the material. Thereafter, the material is subjected to a drawing or rolling work so that a multiplicity of minute cracks in the desired state are formed in the surface of the material. This method relying upon the drawing or rolling work eliminates the problem of the limitation with respect to the material almost completely.